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Accumulation of polyphosphate in Lactobacillus spp. and its involvement in stress resistance.
- Source :
-
Applied and environmental microbiology [Appl Environ Microbiol] 2014 Mar; Vol. 80 (5), pp. 1650-9. Date of Electronic Publication: 2013 Dec 27. - Publication Year :
- 2014
-
Abstract
- Polyphosphate (poly-P) is a polymer of phosphate residues synthesized and in some cases accumulated by microorganisms, where it plays crucial physiological roles such as the participation in the response to nutritional stringencies and environmental stresses. Poly-P metabolism has received little attention in Lactobacillus, a genus of lactic acid bacteria of relevance for food production and health of humans and animals. We show that among 34 strains of Lactobacillus, 18 of them accumulated intracellular poly-P granules, as revealed by specific staining and electron microscopy. Poly-P accumulation was generally dependent on the presence of elevated phosphate concentrations in the culture medium, and it correlated with the presence of polyphosphate kinase (ppk) genes in the genomes. The ppk gene from Lactobacillus displayed a genetic arrangement in which it was flanked by two genes encoding exopolyphosphatases of the Ppx-GppA family. The ppk functionality was corroborated by its disruption (LCABL_27820 gene) in Lactobacillus casei BL23 strain. The constructed ppk mutant showed a lack of intracellular poly-P granules and a drastic reduction in poly-P synthesis. Resistance to several stresses was tested in the ppk-disrupted strain, showing that it presented a diminished growth under high-salt or low-pH conditions and an increased sensitivity to oxidative stress. These results show that poly-P accumulation is a characteristic of some strains of lactobacilli and may thus play important roles in the physiology of these microorganisms.
- Subjects :
- Culture Media chemistry
Gene Deletion
Hydrogen-Ion Concentration
Lactobacillus enzymology
Lactobacillus genetics
Lactobacillus metabolism
Microscopy
Osmotic Pressure
Oxidative Stress
Phosphotransferases (Phosphate Group Acceptor) genetics
Phosphotransferases (Phosphate Group Acceptor) metabolism
Salts
Cytoplasmic Granules metabolism
Lactobacillus physiology
Polyphosphates metabolism
Stress, Physiological
Subjects
Details
- Language :
- English
- ISSN :
- 1098-5336
- Volume :
- 80
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Applied and environmental microbiology
- Publication Type :
- Academic Journal
- Accession number :
- 24375133
- Full Text :
- https://doi.org/10.1128/AEM.03997-13